In order to understand their interaction with the gases, two types of sensitive materials are investigated - semiconducting metal oxides (SMOX) and polymers. In both cases, all investigation techniques are used in sensor operation conditions (operando) meaning that the samples are fabricated in the same way in which the real sensors are (e.g. the SMOX are deposited as polycrystalline, thick, porous films onto substrates provided with electrodes and heaters) and are studied in real-life like conditions (heated between 200 and 400°C for the SMOX, at normal pressure, in the presence of humidity and of the target gases). Most of the operando experiments are performed in-house; for SMOX they include: DC resistance, AC impedance spectroscopy, work function changes (Kelvin probe), catalytic conversion and Diffuse Reflectance Infrared Fourier Transformed Spectroscopy (DRIFTS) measurements.
On the side of technology, the group invented, developed and transferred to the industry - by spinning off a company, AppliedSensors GmbH - SMOX microsensor technology that combines thick film sensing layers with micro hotplates. To date, more than 6 million sensors were commercialized. The current development are focused on: a novel SMOX sensor fabrication technology - in cooperation with the University of Bremen - based on Flame Spray Pyrolysis (FSP) one step synthesis and layer deposition; and on integration of polymer and SMOX sensing layers onto flexible/plastic substrates - in cooperation with EPF Lausanne.